(Sorry to pick on Ben, I was looking for that awful 'highlight' image and pulled stuff he oneboxed as examples while I looked for it :P)

In these cases, flagging is not really appropriate. I could ask someone to edit it to a URL (or ask a mod, or in my case, do it myself :P) but this is kind of a poor solution. Other people might be interested in the content, or having their own conversation to which the oneboxed content is appropriate.

I'd like some way to "un-onebox" an item. That is, some button or method to replace the oneboxed content with the URL, or collapse it with some placeholder that could be clicked to view the content.

Ideally, I could preemptively "un-onebox" things I don't care about, or items from users that consistently post content I'm not interested in. For example, perhaps I don't want twitter or amazon to onebox on my chat, or I know that a particular person is highly likely to post things I'm uninterested in.

I've been considering doing this myself somehow, but reverse engineering the minified chat system is kind of painful. People seemed to react positively to the concept, however.